An image sensor may be a semiconductor device that may convert optical images into electrical signals. Examples of an image sensor may include charged coupled devices (CCDs) and complementary metal oxide semiconductor (CMOS) image sensors.
In a method for manufacturing an image sensor, transistors and photodiodes, which may be electrically connected to the transistors, may be formed on a semiconductor substrate. An interlayer insulating layer and a line may be formed on the transistors and the photodiodes. Subsequently, microlenses, which may provide condensed light onto the photodiodes, may be formed on the interlayer insulating layer.
In an image device, incident light from an outside source may be condensed by the microlenses and may pass through the interlayer insulating layer and may be incident onto the photodiodes. A portion of light incident from the outside may be absorbed in the interlayer insulating layer. Hence, an amount of light that actually reaches the photodiodes may be different from an amount of light before the light passes through the interlayer insulating layer. This may reduce certain characteristics of the image device.